1/*
2 * Copyright (c) 2004-2005 Todd C. Miller <[email protected]>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17#ifndef HAVE_CLOSEFROM
18
19#include <sys/types.h>
20#include <sys/param.h>
21#include <unistd.h>
22#include <stdio.h>
23#ifdef HAVE_FCNTL_H
24# include <fcntl.h>
25#endif
26#include <limits.h>
27#include <stdlib.h>
28#include <stddef.h>
29#include <string.h>
30#include <unistd.h>
31#ifdef HAVE_DIRENT_H
32# include <dirent.h>
33# define NAMLEN(dirent) strlen((dirent)->d_name)
34#else
35# define dirent direct
36# define NAMLEN(dirent) (dirent)->d_namlen
37# ifdef HAVE_SYS_NDIR_H
38# include <sys/ndir.h>
39# endif
40# ifdef HAVE_SYS_DIR_H
41# include <sys/dir.h>
42# endif
43# ifdef HAVE_NDIR_H
44# include <ndir.h>
45# endif
46#endif
47
48#include "compat.h"
49
50#ifndef OPEN_MAX
51# define OPEN_MAX 256
52#endif
53
54#if 0
55__unused static const char rcsid[] = "$Sudo: closefrom.c,v 1.11 2006/08/17 15:26:54 millert Exp $";
56#endif /* lint */
57
58/*
59 * Close all file descriptors greater than or equal to lowfd.
60 */
61#ifdef HAVE_FCNTL_CLOSEM
62void
63closefrom(int lowfd)
64{
65 (void) fcntl(lowfd, F_CLOSEM, 0);
66}
67#else
68void
69closefrom(int lowfd)
70{
71 long fd, maxfd;
72#if defined(HAVE_DIRFD) && defined(HAVE_PROC_PID)
73 char fdpath[PATH_MAX], *endp;
74 struct dirent *dent;
75 DIR *dirp;
76 int len;
77
78 /* Check for a /proc/$$/fd directory. */
79 len = snprintf(fdpath, sizeof(fdpath), "/proc/%ld/fd", (long)getpid());
80 if (len > 0 && (size_t)len <= sizeof(fdpath) && (dirp = opendir(fdpath))) {
81 while ((dent = readdir(dirp)) != NULL) {
82 fd = strtol(dent->d_name, &endp, 10);
83 if (dent->d_name != endp && *endp == '\0' &&
84 fd >= 0 && fd < INT_MAX && fd >= lowfd && fd != dirfd(dirp))
85 (void) close((int) fd);
86 }
87 (void) closedir(dirp);
88 } else
89#endif
90 {
91 /*
92 * Fall back on sysconf() or getdtablesize(). We avoid checking
93 * resource limits since it is possible to open a file descriptor
94 * and then drop the rlimit such that it is below the open fd.
95 */
96#ifdef HAVE_SYSCONF
97 maxfd = sysconf(_SC_OPEN_MAX);
98#else
99 maxfd = getdtablesize();
100#endif /* HAVE_SYSCONF */
101 if (maxfd < 0)
102 maxfd = OPEN_MAX;
103
104 for (fd = lowfd; fd < maxfd; fd++)
105 (void) close((int) fd);
106 }
107}
108#endif /* !HAVE_FCNTL_CLOSEM */
109#endif /* HAVE_CLOSEFROM */
110